Intermittently-operating electric regulator



' 3,657 05 6 A. YTTERBERG ET AL INTERMITTE'NTLY OPERATING ELECTRICREGULATOR Filed April 22. 1926 AR LE YTTE R BERG AAGE. GARDE \NVENTORSQL MM AT-TO R n EY,

Patented Jan. 24, 1928.

UNITED STATES PATENT OFFICE.

ABLE YT'IERBERG, OE LUDVIKA, A ND AAGE GARDE, OF VASTERAS, SWEDEN, AS-

SIGNORS TO ALLMKNNA. SVENSKA. ELEKTBISKA AKTIEBOIAGET, OI VASTERLS,

SWEDEN, A CORPORATION OF SWEDEN.

INTERMITTENTLY-OPERATING ELECTRIC REGULATOR Application filed.Apri1 22,1926, Serial No. 103,695, andin Sweden April 3, 1925.

Our invention relates to regulators for dynamo-electric machinery andmore particularly to the type where the regulating is effected byintermittently short-circuiting a portion of a circuit, for instancecontaining a field resistor. The regulating may be applied to voltage,current, speed, or any other quantity of the machinery capableof beingregulated in an analogous manner.

One object of our invention is to provide a regulator which is Verylight, handy and simple in construction.

Another object of our invention is to provide a regulator capable ofdirectly (without the use of an intermediary relay) controlling largercurrents than has been possible heretofore.

The intermittently acting regulators as heretofore constructed generallycomprise an oscillating armature carrying a contact and another armaturesupporting the pivot of oscillation for the former. The latter armatureis actuated by a coil energized according to the quantity to be keptconstant (for instance the voltage of a main generator), while theformer armature is actuated by a coil energized by a quantitycontrolling-the former (for instance the voltage of an ex-= citer). Thelatter quantity oscillates about a medium value which is, however, notconstant but depends on certain factors (for instance the load on themain generator). For this reason, the medium position about which thefirst-named armature oscillates cannot be, constant, and therefore thepivot of oscillation must also be movable. All

these circumstances result in a rather com plicated construction andalso in a rather hazardous operation of the contacts which makes itimpossible for these to control comparatively large currents.

According to our present invention, a single movable member is employedwhich oscillates around a stationary axis and carries one of thecontacts while the other contact is stationary. The saidoscillatingmember is acted upon by the regulated quantity (e. g. maingenerator voltage) as well as by the quantity oscillating in value, butthe action of the former, when normal, is compensated for instance by aspring, and the mean value of the latter is compensated by electricalmeans which shall be described hereinafter. In this way, the oscillatingmember can be tion ofthe main quantities determining the operation ofthe regulator, shown as a function of time, and Fig. 3 is a view showinga detail of construction.

Referring to Fig. 1, 11 is the armature winding and 12 the excitingwinding of a main generator. The latter winding is fed from an excitinggenerator having an armature winding 61 and an exciting winding 62. Aresistor 63 connected in series with the latter is intermittentlyshort-circuited by the regulator, whereby the voltage is regulated in amanner known in principle.

The regulator proper comprises an oscillating member 41 actuated by twomagnetic fields having cores 31, 51. One of the'fields is generated by astationary winding 32 actuated by the voltage of the main generator.

As in the example shown the latter is supposed to be an alternatingcurrent generator, it is connected to the winding 32 over a voltagetransformer 13. The field generated by the coil 32 acts on a coil 35supported by the member 41, the said coil 35 being in series with thecoil 32 and thus also actuated by a current proportional to the voltageof the main generator. The force acting upon the coil 35 will thus besubstantially proportional to the square of the generator voltage, andthe winding directions of the coils are preferably such as to make thisforce attractional..

The other field acting on the member 41 and having the core 51' issupposed to be constant and unidirectional and may for instance begenerated by permanent magnetism. It acts on a coil'52 supported by themember 41 and fed in a manner characteristic to the invention which willbe described later. The member 41 further supports a contact 44performing the aforesaid intermittent short-circuiting of the resistor(53. It swings in a knife-ed e bearing 42, whlle the current is admittedy means of flexible conductors 47 and 48. The coils and 42 can beconveniently supported by the memher 41 as shown in Fig. 3, the frame ofwhich member can serve as common return conductor for-said coils.

The coil 52 is actuated by the voltage of the exciting generator,however not directly but in such a manner that the constant portion ofthe said voltage is filtered away.

' a tertiary winding 56 connected to a condenser 57 for delivering itsvmagnetizing current. .A corresponding winding with a condenser may bearranged also in any other suitable place, for instance on the core 31.

The member 41 is also actuated by a spring 43 counteracting the forcebetween 86 the coils 32 and 35. This force being supposed to beconstant, as the regulator is intended to regulate upon constantvoltage,

the member can normally be considered to be actuated only by theoscillating force set up by the coil 52 in the constant magnetic field,by the unbalanced spring force caused under oscillation (when the springis alternately stretched and contracted), and in some cases, if it isnot counterbalanced with respect to its axis, by gravity. All theseorces are more or less accurately harmonic 1n nature and thus will causea harmonicswinging of the member 41. What has a tendency to disturb thisharmonic swinging is practically only the contact pressure, but yarranging the movable contact in some suitable manner also thisdisturbing action ,may be considerably reduced. A suitable arrangementof the movable contact has been found to be to suspend it in a hinge 46practically coaxial with the knife-edge hearing 42 by a comparativelyrigid member 45 and connect the latter to the member 41 by one or moreweak springs 49. In this way, it is possible to avoid any sliding at thecontacts which is objectionable in this apparatus. If the member 41 isbalanced around its axis, two contacts balancing each other are alsopreferably employed.

The general manner of operation of the apparatus shall now-be described,reference being bad particularly to Fig. 2 of the drawing. The curve 8represents the path of the member 41 and the curve 2) its velocity, bothas functions of time. As long as the voltage of the main generator isconstant, these will be practically sine-shaped. By reason of i thedecidedly elastic'connection between the member 41 and the movablecontact or contacts, the latter will rest against the correspondingstationary contact or contacts during practically one half of each cycleof oscillation of the member 41. The semicycles corresponding to closedcontacts are marked by full-drawn, the semi-cycles cortransformer itselffree from magnetic leak-' age, the current through the'coil '52 wouldfollow practically the same curve as the voltage E, but on account ofthe inductance the real current I becomes more or less displaced inphase from the voltage-and in the same time its curve obtains a morerounded shape. At any rate, it obtains a'component inphase with thevelocity '0, such a component being just required for compensating thedamping by friction and the like which is always more or lessproportional to the velocity. The mechanical characteristics of themember 41 should preferably be such that it will swing practically inresonance with the electric impulses. When the voltage of the maingenerator is changed .by some reason, for instance a change in load, theabove-described quasistationary conditions are disturbed. The forcebetwen the coils 32, 35' and that exerted by the spring 43 no longerkeep each other in equilibrium, but either of these (depending onwhether the voltage is raised or lowered) becomes predominant. As themember 41 is very light compared with these forces, it willinstantlystop its motion and come to rest in one of its end positions,corresponding to open or closed contacts. The voltage of the excitergenerator will then be 'very rapidly lowered or raised, until thevoltage of the main generatoris restored to its normal value, when themember 41 resumes its. harmonic oscillation. It is to be noted, that thetime intervals corresponding to open and closed contacts will still beequal, this condition corresponding to constant (high or low) value ofthe exciter voltage (as long as the machine operates on the straightportion of its magnetizin curve), while difi'erent intervals of closeand open contacts would correspond to a time variation of the excitervoltage. The

only difference caused in Fig. 2 when the 139 ing about ried by saidmember and responsive to the emons exciter voltage is made higher orlower, is that the branches of the curve E will be higher and steeperand the amplitude of the curve I correspondingly larger.

Instead of using a separate transformer between the exciter and the coil52, the latter may be connected to an extra winding on the field of theexciter. Instead of directly short-circuiting the resistor 63 by meansof the contacts 44 the said short-circuiting may be efi'ected by anintermediary relay.

We claim as our invention:

1. In regulating systems for dynamo-electric machinery, an oscillatingmember carrying electromagnetic means responsive to the action of thequantity to be regulated, contact means carried by said oscillatingmember and adapted to short-circuit a portion of an electric circuit,electromagnetic means carried by said oscillating member and responsiveto the action of an electric quantity altered by said short-circuitingand means for compensating the action, upon said oscillating member, ofa certain portion of the quantity to be regulated and of the quantityaltered by said short-circuiting.

' 2. In regulating systems for dynamo-electric machinery, a membercapable of oscillat:

an axis, electromagnetic means caraction of the quantity to beregulated, a spring connected to said oscillating member and normallycompensating the action of said electromagnetic means, contact meanscarried by 'said oscillating member and adapted to short-circuit aportion of an electric circuit, electromagnetic means carried by saidoscillating member and responsive to the action of an electric quantityaltered by said short-circuiting, and means for compensating the action,upon said oscillating member, of the mean value of said last-mentionedelectric quantity, v

3. In regulating systems for dynamo-electric machiner a member capableof oscillat ing about an exciter,

axis, electromagnetic means tities of said circuit to aifect saidoscillating member.

4. In regulating systems for dynamo-electric machinery, a maingenerator, an exciter therefor, a resistor in the field circuit of saidan oscillating regulator member, contacts controlled by said member ,andadapted to intermittently short-circuit said resistor, electromagneticmeans carried by said oscillating member and responsive to an electricalcharacteristic of said main generator, a transformer connected on itsprimary side to the terminals of said exciter and electromagnetic meanscarried by said oscillating member, responsive to the secondary currentof said transformer.

5. In electric regulators adapted to operate by intermittentlyshort-circuiting a portion of an electric circuit, an oscillatorymember, contact means for said short-circuitin carried thereby, twocoils adapted to be ed by different circuits carried by said oscillatorymember, stationary magnet cores adjacent to each oi the paths of saidcoils, and means for maintaining, in one of said cores, a constantfield, and in the other core a field proportional to the currenttraversing the coil moving adjacent thereto,

In testimony whereof we have signed our names to this specification.

ABLE r'rrnnnnns. AAGE sense.

